NWS Weekend Discussion

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TALLAHASSEE FL
705 PM EST Fri Feb 3 2012
.SYNOPSIS...
AT UPPER LEVELS...
The large scale longwave pattern is highlighted by a large TROUGH
from WRN Great Lakes SWWD to Desert SW with large upper CUTOFF low
over SW KS driving a WINTERSTORM. East of this trough, ridging
dominates SE region. A rather dense MID level 9-11K and CIRRUS
canopy emanating from the trough has overspread this region
moderating temperatures.
Through the weekend, the low is forecast to weaken AS it gets left
behind by the faster northern stream FLOW across the Great Lakes. A
series of upper impulses will move EWD but remain well N of CWA. By
12z Sun it should located near the KS/MO border. The end result of
this is a rather suppressed mid and upper level pattern across the
Southeast.
AT LOWER LEVELS...
Analysis shows strong HIGHPRESSURE in place across NC with ridging
down across FL, and a potent low over across the Eastern most
Colorado with cold FRONT SSW to low over SW OK and a warm front SEWD
into NRN Gulf. In between, SLY flow was advecting a good amount of
Gulf MOISTURENEWD across the Central Gulf States with a more
modified airmass in place across our region.
Overnight, high pressure will move ESE into the Wrn ATLC allowing
the weak warm front to lift north As a result, local winds shift to
a more sly component allowing more low level moisture to lift
northward ahead of the next storm system and produce some showers
and possibly some FOG. However, with high ridging SWD local
winds will remain above NORMAL. Warm front will lift further NWD on
Saturday with rain shutting off from S-N. High will shift further
SEWD ahead of next cold front with a better CHANCE of fog SATNIGHT.
Above low will REACH" onClick="return popup(this, 'notes')">REACH SRN MO Sat morn then to KY/TN in the EVE to
further weaken over mid-ATLC states on Sun. Assocd cold front will
weaken and extend from Srn MO SWWD to TX Sat morn then, front will
move into the region Saturday night into Sunday. Expect cloudy skis,
high HUMIDITY and mild temps ahead of front in warm sector. Absent
upper level support, WIDESPREADSHOWER activity is not anticipated.
&&
.SHORT TERM...(REST OF TONIGHT THROUGH EARLY SATURDAY). Expect lows
mid 50s inland to around 60 at coast. Showers weakening this eve as
they run into drier AIR s of warm front boundary so lowered POPS,
especially east of Apalachicola River. Sharp 50-20% NW-SE rain POPGRADIENT decreasing to 40-0% after 06z.
&&
.AVIATION...
VFR conditions will generally prevail through the remainder of the
evening despite periodic showers between KDHN and KABY. After
midnight, a trend toward higher areal coverage of MVFR cigs/VIS will
begin and have all terminals with a period of MVFR restrictions
during the later night hours into the first FEW daylight hours of
Saturday. It is not out of the question to see a few brief periods
of IFR, however confidence is not high enough in these restrictions
to include with this TAF package. CIGS/VIS will lift back above VFR
levels by midday Saturday and through the afternoon hours. Have
added a prob30 grouping for a "pop up" shower or storm during the
afternoon hours around KDHN and KABY.
&&
.MARINE...Winds and SEAS are expected to remain elevated tonight as
strong high pressure remains in place north of the region across the
Mid Atlantic States. As the RIDGE moves eastward into the Atlantic,
winds and seas will diminish by Saturday Night with relatively low
winds and seas remaining in place throughout the remainder of the
weekend. A cold front will move across the waters Sunday Night
resulting in a slight increase in offshore winds.